blocks|key|1067853|text|您可以实现此委托方法，它返回一个CGFloat|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1067854|-+(CGFloat)pickerView:(UIPickerView+*)pickerView+widthForComponent:(NSInteger)component|offset|length|style|CODE|1067855|在选取器视图上调用此函数以确定行宽。|1067856|entityMap^0|0|0|2F|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@$D|N|E|O|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|P|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

You can implement this delegate method, which returns a CGFloat

<code>- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component</code>

This is called on the picker view to determine row width.

blocks|key|4735070|text|-+(UIView+*)pickerView:(UIPickerView+*)pickerView+viewForRow:(NSInteger)row+forComponent:(NSInteger)component+reusingView:(UIView+*)view
{
++++UILabel+*label+=+[[UILabel+alloc]+initWithFrame:CGRectMake(0,+0,+300,+37)];
++++label.text+=+[NSString+stringWithFormat:@"something+here"];
++++label.textAlignment+=+NSTextAlignmentCenter;+//Changed+to+NS+as+UI+is+deprecated.
++++label.backgroundColor+=+[UIColor+clearColor];
++++[label+autorelease];
++++return+label;
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4735071|或者像这样的东西。|unstyled|4735072|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
 UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 300, 37)];
 label.text = [NSString stringWithFormat:@"something here"];
 label.textAlignment = NSTextAlignmentCenter; //Changed to NS as UI is deprecated.
 label.backgroundColor = [UIColor clearColor];
 [label autorelease];
 return label;
}
</code></pre>

or something like this.

blocks|key|4735105|text|请记住，中的视图|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4735106|-+(UIView+*)pickerView:(UIPickerView+*)pickerView+viewForRow:(NSInteger)row+forComponent:(NSInteger)component+reusingView:(UIView+*)view|code-block|syntax|javascript|4735107|实际上是一个UITableViewCell，所以您可以像这样使用它：|4735108|-+(UIView+*)pickerView:(UIPickerView+*)pickerView+viewForRow:(NSInteger)row+forComponent:(NSInteger)component+reusingView:(UIView+*)view
{
++++static+NSString+*cellIdentifier+=+@"pickerViewCell";
++++UITableViewCell+*cell+=+(UITableViewCell*)view;

++++if(cell==nil)
++++{
++++++++cell+=+[[[UITableViewCell+alloc]+initWithStyle:UITableViewCellStyleDefault+reuseIdentifier:cellIdentifier]+autorelease];
++++++++/**+customize+the+cell+**/
++++}

++++/**+set+the+label+**/
++++cell.textLabel.text+=+[dataSource+objectAtIndex:row];

++++return+cell;
}|4735109|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Remember, the view in 

<pre><code>- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
</code></pre>

is actually a UITableViewCell, so you can work with it like:

<pre><code>- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
 static NSString *cellIdentifier = @"pickerViewCell";
 UITableViewCell *cell = (UITableViewCell*)view;

 if(cell==nil)
 {
 cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellIdentifier] autorelease];
 /** customize the cell **/
 }

 /** set the label **/
 cell.textLabel.text = [dataSource objectAtIndex:row];

 return cell;
}
</code></pre>

blocks|key|4735121|text|现在在iOS+6中更简单了一点...您可以实现一个新方法来返回属性字符串...您还可以在属性字符串中定义对齐方式。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4735122|-+(NSAttributedString+*)pickerView:(UIPickerView+*)pickerView+attributedTitleForRow:(NSInteger)row+forComponent:(NSInteger)component+{
++++NSString+*text+=+[NSString+stringWithFormat:@"R%25d+C%25d",+row,+component];
++++NSMutableAttributedString+*as+=+[[NSMutableAttributedString+alloc]+initWithString:text];
++++NSMutableParagraphStyle+*mutParaStyle=[[NSMutableParagraphStyle+alloc]+init];
++++mutParaStyle.alignment+=+NSTextAlignmentCenter;
++++[as+addAttribute:NSParagraphStyleAttributeName+value:mutParaStyle+range:NSMakeRange(0,[text+length])];
++++return+as;
}|code-block|syntax|javascript|4735123|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

A little easier now in iOS 6... There's a new method you can implement to return an attributed string... And you can define alignment in attributed strings.

<pre><code>- (NSAttributedString *)pickerView:(UIPickerView *)pickerView attributedTitleForRow:(NSInteger)row forComponent:(NSInteger)component {
 NSString *text = [NSString stringWithFormat:@"R%d C%d", row, component];
 NSMutableAttributedString *as = [[NSMutableAttributedString alloc] initWithString:text];
 NSMutableParagraphStyle *mutParaStyle=[[NSMutableParagraphStyle alloc] init];
 mutParaStyle.alignment = NSTextAlignmentCenter;
 [as addAttribute:NSParagraphStyleAttributeName value:mutParaStyle range:NSMakeRange(0,[text length])];
 return as;
}
</code></pre>

blocks|key|1067937|text|下面的一个也可以正常工作-|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1067938|-+(UIView+*)pickerView:(UIPickerView+*)pickerView+viewForRow:(NSInteger)row+forComponent:(NSInteger)component+reusingView:(UIView+*)view
{
++++UILabel+*lbl+=+[[UILabel+alloc]+initWithFrame:CGRectMake(0.0f,+0.0f,+[pickerView+rowSizeForComponent:component].width,+[pickerView+rowSizeForComponent:component].height)];
++++lbl.text+=+[reservePickerArray+objectAtIndex:row];
++++lbl.adjustsFontSizeToFitWidth+=+YES;
++++lbl.textAlignment=UITextAlignmentCenter;
++++lbl.font=[UIFont+systemFontOfSize:20];
++++return+lbl;
}|code-block|syntax|javascript|1067939|干杯！！|1067940|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Below one also working fine - 

<pre><code>- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view
{
 UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(0.0f, 0.0f, [pickerView rowSizeForComponent:component].width, [pickerView rowSizeForComponent:component].height)];
 lbl.text = [reservePickerArray objectAtIndex:row];
 lbl.adjustsFontSizeToFitWidth = YES;
 lbl.textAlignment=UITextAlignmentCenter;
 lbl.font=[UIFont systemFontOfSize:20];
 return lbl;
}
</code></pre>

Cheers!!

blocks|key|1887276|text|我知道这个问题没有标记为swift，但如果有人正在寻找Swift+3.0版本，它就在这里。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1887277|/*+Called+by+the+picker+view+when+it+needs+the+view+to+use+for+a+given+row+in++++
+a+given+component.+If+the+previously+used+view+(the+view+parameter)+is+adequate,++++
+return+that.+If+you+return+a+different+view,+the+previously+used+view+is+++++
released.+The+picker+view+centers+the+returned+view+in+the+rectangle+for+row.++++

+*/
func+pickerView(_+pickerView:+UIPickerView,+viewForRow+row:+Int,+forComponent+component:+Int,+reusing+view:+UIView?)+->+UIView+{

++++var+label+=+UILabel(frame:+CGRect(x:+CGFloat(0),+y:+CGFloat(0),+width:+CGFloat(300),+height:+CGFloat(37)))


++++let+booking+=+self.bookingInfo[row]++//bookingInfo+is+an+array+of+elements
++++++label.text+=+String(booking.BookingNumber)+%2B+String(booking.DateAndTime)
++++++++label.textAlignment+=+.left
+++++++++return+label
}|code-block|syntax|javascript|1887278|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I know this question is not tagged for swift, but just in case somebody is looking for the Swift 3.0 version, here it is. 

<pre><code>/* Called by the picker view when it needs the view to use for a given row in 
 a given component. If the previously used view (the view parameter) is adequate, 
 return that. If you return a different view, the previously used view is 
released. The picker view centers the returned view in the rectangle for row. 

 */
func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -&gt; UIView {

 var label = UILabel(frame: CGRect(x: CGFloat(0), y: CGFloat(0), width: CGFloat(300), height: CGFloat(37)))


 let booking = self.bookingInfo[row] //bookingInfo is an array of elements
 label.text = String(booking.BookingNumber) + String(booking.DateAndTime)
 label.textAlignment = .left
 return label
}
</code></pre>

blocks|key|4735210|text|只需将宽度设置为视图的宽度，文本将自动居中：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4735211|-+(CGFloat)pickerView:(UIPickerView+*)pickerView+widthForComponent:(NSInteger)component+{
++++return+self.view.bounds.size.width;+
}|code-block|syntax|javascript|4735212|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Just set the width to the width of the view and the text will center automatically:

<pre><code>- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {
 return self.view.bounds.size.width; 
}
</code></pre>

blocks|key|1887291|text|将James+Boutcher升级为swift+5.我预先计算，而OP直接在attributedTitleForRow中进行属性分配|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1887292|++++pickerData+=+pickerData.map+{
++++++++let+ps+=+NSMutableParagraphStyle()
++++++++ps.alignment+=+.center;

++++++++let+paraAttributes:[NSAttributedString.Key+:+Any]+=+[+NSAttributedString.Key.paragraphStyle:+ps]

++++++++let+res+=+NSMutableAttributedString(attributedString:+$0)
++++++++res.addAttributes(paraAttributes,+range:+NSRange(location:+0,+length:+res.length))
++++++++return+res
++++}|code-block|syntax|javascript|1887293|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Modernized James Boutcher to swift 5.
I precompute while the OP does an attribution directly in attributedTitleForRow

<pre><code> pickerData = pickerData.map {
 let ps = NSMutableParagraphStyle()
 ps.alignment = .center;

 let paraAttributes:[NSAttributedString.Key : Any] = [ NSAttributedString.Key.paragraphStyle: ps]

 let res = NSMutableAttributedString(attributedString: $0)
 res.addAttributes(paraAttributes, range: NSRange(location: 0, length: res.length))
 return res
 }
</code></pre>

blocks|key|1068047|text|我花了很长时间才意识到我遗漏了这一行代码：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1068048|pickerView.autoresizingMask+=+.flexibleWidth|offset|length|style|CODE|1068049|entityMap^0|0|0|18|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

It took me a long time to realize I'm just missing this single line of code:

<code>pickerView.autoresizingMask = .flexibleWidth</code>

So I have a uipickerview with rows that only contain the number 0-24 and it looks a bit silly since the numbers are left aligned leaving a huge gap on the right of the pickerview.

Is there an easy way to center align text in a uipickerview?

Center UIPickerView Text

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

所以我有一个uipickerview，它的行只包含数字0-24，它看起来有点傻，因为数字左对齐，在选择器视图的右边留下了一个巨大的间隙。在uipickerview中有没有简单的居中对齐文本的方法？

问将UIPickerView文本居中
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问将UIPickerView文本居中EN